1. Field of the Invention
The present invention relates to electrical cable connectors, such as loadbreak connectors and deadbreak connectors, and more particularly to an electrical cable connector, such as a power cable elbow connector, having a voltage detection point insulation shield, which is provided during a molding process to preserve the critical electrical interfaces of the connector.
2. Description of the Prior Art
Loadbreak cable connectors used in conjunction with 15, 25 and 35 kV switchgears generally include a power cable elbow connector having one end adapted for receiving a power cable and another end adapted for receiving a loadbreak bushing insert. The end adapted for receiving the bushing insert generally includes an elbow cuff for providing an interference fit with a molded flange on the bushing insert. This interference fit between the elbow cuff and the bushing insert provides a moisture and dust seal therebetween. An indicator band may be provided on a portion of the loadbreak bushing insert so that an inspector can quickly visually determine proper assembly of the elbow cuff and the bushing insert.
Such loadbreak elbows typically comprise a conductor surrounded by a semiconducting layer and an insulating layer, all encased in a semiconductive outer shield. The elbow connector further includes a test point terminal embedded in the insulating sheath and exposed for contact from outside of the shield. A voltage on the conductor capacitively couples a first voltage on the test point terminal and a second voltage on the outer shield.
Service personnel commonly encounter difficulty in reliably determining whether or not a voltage is present on a loadbreak elbow. This is of considerable importance, since the safety of service personnel effecting service on such a system may depend upon the reliability of a status indicator correctly indicating the status of the connector to prevent electrical shock hazards.
A variety of indicating devices for such purpose are known. These devices must be carefully employed in order to avoid electrical shock and draw a current from the conductor being tested which can affect the voltage reading. Failure of the device could indicate a false voltage status which may lead service personnel to assume that there is no voltage on the conductor when a voltage is in fact present, which presents an obvious safety hazard.
Electrical shock hazards can also arise when the test point terminal and the area surrounding the terminal are not carefully manufactured or are subject to debris and contaminants. For example, irregularities, voids and even mold parting lines formed in the surfaces surrounding the voltage test point terminal may increase the chances of an electrical short and/or failure. Such irregularities in these surfaces further often interfere with effective sealing of the protective cap used to cover the terminal when not in use. Without an effective seal, dirt and other contaminants may find their way to the terminal, which presents a safety and performance hazard.
These concerns are significant given the problems typically encountered during manufacturing of these types of connectors. Typically, these connectors are made by injection molding of a rubber or an epoxy material wherein the critical electrical interfaces adjacent the voltage detection point are formed by molding the material against a metal mold surface. To prevent the material from sticking to the mold surface, release agents are typically sprayed in the mold cavities. Once cured, the connector is removed from the mold and, due to the nature of the molding material, a considerable amount of mold flashing must be trimmed. Even when trimmed properly, mold parting lines on the connector interface surfaces may disrupt the required protective cap seal and result in an electrical short. Also, the mold cavities are typically prone to contaminants, which may in turn be imparted onto the electrical interface of the connector resulting in a scrapped part.
Accordingly, it would be advantageous to provide a method for manufacturing a molded electrical connector which reduces or prevents the aforesaid manufacturing problems. It would also be desirable to provide an electrical cable connector having an improved insulation shield adjacent the connector's voltage detection point terminal which enhances safety and performance.